The present invention relates generally to web browsers and deals more particularly with a web browser which automatically checks availability of hot links on a displayed web page before the user selects the hot links.
The world wide web (WWW) comprises a multitude of computer servers, respective databases which are managed by the servers and contain web pages and a network by which clients can communicate with the servers and thereby request and load web pages of interest. Each of the clients includes a "web browser" which is an interface to the user and the WWW. One common web browser is the Netscape Navigator (tm) web browser licensed by Netscape Communications Corporation. The Netscape Navigator web browser is further described in "Hands on Netscape" by David Sachs, Prentice Hall, Upper Saddle River, N.J., 1996 ISBN013240284X.
Each web page has a "URL" address which comprises an access method/protocol designation such as hypertext transport protocol (HTTP) as a prefix, a server name, and the requested data as a suffix. The server name typically includes a "domain name" which is the name of a company, educational institution or other organization that owns the server. The request indicates a web page associated with the server. There are different ways that a client can obtain a web page. If the client knows the URL, the client can directly request the web page from the server. However, if the client only knows the server name, the client can address the server name and in response, the server will present the "home page" for the server. The home page (and other web pages) typically includes tags or "hot links" which reference other associated web pages. When the user selects a hot link, the web browser requests the respective web page from the corresponding server.
In recent years there has been a large increase in the number of servers, web pages and "network traffic" on the WWW. The expansion of the WWW, while advantageous for information exchange, has lead to various problems. The network may become congested, slowing or even preventing traffic. A server may be too busy with other requests to service every request it receives. A server may even be deleted altogether although it continues to be addressed via hot links of various web pages. Many web pages are not managed properly and some have been deleted altogether although they continue to be referenced by hot links on other web pages. Consequently, when a user requests a web page by a hot link or URL, often the web page cannot be accessed immediately or ever for that matter. This wastes the user's time and causes dissatisfaction with the WWW.
An IBM Web Browser Intelligence tool gives the user valuable information to avoid some of the time wastage. The IBM Web Browser Intelligence tool automatically "pings" each server referenced by a hot link on a web page when the web page is initially loaded and displayed. If the server is in existence and is available to process the ping request, the server responds with a simple acknowledgment of its existence. The IBM Web Browser Intelligence tool also estimates the time required to fetch web pages managed by this server by measuring the time between the sending of the ping request and receipt of an acknowledgment from the server. (The actual fetch time will also depend on the length of the HTML and associated graphics and the performance and workload of the server and web page storage media when the actual fetch request is made). The IBM Web Browser Intelligence tool then indicates to the user which servers currently exist and the approximate fetch rate as follows. Red dots adjacent to a hot link indicate that the server is not currently available or very slow to respond. Yellow dots adjacent to a hot link indicate that the respective server is currently available but the fetch rate is slow. Green dots adjacent to a hot link indicate that the respective server is currently available and the fetch rate is fast. The IBM Web Browser Intelligence tool re-pings each server associated with each hot link at a user specified interval to update the availability status of every hot link. Despite the significant value of the IBM Web Browser Intelligence tool, it does not determine whether particular web pages managed by the server are available.
Another web browser tool actually loads into a client buffer all web pages referenced by the hot links on another web page when this other web page is initially loaded and displayed. This makes the hot linked web pages immediately available to the user when the user selects the hot links. However, this web browser tool causes substantial network traffic to load all the web pages, and the user will not ordinarily want to view the web pages referenced by all hot links of the displayed web page.
A general object of the present invention is to automatically determine availability of web pages referenced by hot links on a displayed web page before the user selects the hot links.
A more specific object of the present invention is to make this determination without congesting the network.
Another specific object of the present invention is to periodically and selectively update the availability status of web pages corresponding to the hot links without congesting the network.